Patterns of SARS-CoV-2 Testing Preferences in a National Cohort in the United States: Latent Class Analysis of a Discrete Choice Experiment

Suspected Mpox Symptoms and Testing in Men Who Have Sex With Men in the United States: Cross-Sectional Study

Background

The 2022 mpox outbreak in the United States disproportionately affected gay, bisexual, and other men who have sex with men (GBMSM). Uptake of mpox testing may be related to symptomology, sociodemographic characteristics, and behavioral characteristics.

Objective

This study aimed to describe suspected mpox symptoms and testing uptake among a sample of GBMSM recruited via the internet in the United States in August 2022.

Methods

We conducted a rapid internet-based mpox survey from August 5 to 15, 2022, among cisgender men 15 years and older who had previously participated in the 2021 American Men's Internet Survey. We estimated the prevalence of suspected mpox symptoms (fever or rash or sores with unknown cause in the last 3 mo) and uptake of mpox testing. We calculated adjusted prevalence ratios (aPRs) and 95% CIs for associations between participant characteristics and suspected mpox symptoms and summarized characteristics of GBMSM reporting mpox testing. Among symptomatic GBMSM who did not receive mpox testing, we described testing self-efficacy, barriers, and facilitators.

Results

Of 824 GBMSM, 126 (15.3%) reported at least 1 mpox symptom in the last 3 months; 58/126 (46%) with rash or sores, 57 (45.2%) with fever, and 11 (8.7%) with both. Increased prevalence of suspected mpox symptoms was associated with condomless anal sex (CAS; aPR 1.53, 95% CI 1.06-2.20). Mpox testing was reported by 9/824 GBMSM (1%), including 5 with symptoms. Most GBMSM reporting mpox testing were non-Hispanic White men (7/9 vs 1 Black and 1 Hispanic or Latino man), and all 9 lived in urban areas. Most reported having an sexually transmitted infections test (8/9), 2 or more partners (8/9), CAS (7/9), and group sex (6/9) in the last 3 months. Of those tested, 3 reported living with HIV and all were on treatment, whereas the remaining 6 men without HIV reported current pre-exposure prophylaxis (PrEP) use. Of symptomatic GBMSM who did not report mpox testing, 47/105 (44.8%) had low mpox testing self-efficacy. Among those with low self-efficacy, the most common barriers to testing were not knowing where to get tested (40/47, 85.1%) and difficulty getting appointments (23/47, 48.9%). Among those with high testing self-efficacy (58/105, 55.2%), the most common facilitators to testing were knowing where to test (52/58, 89.7%), convenient site hours (40/58, 69%), and low-cost testing (38/58, 65.5%).

Conclusions

While all GBMSM who reported testing for mpox were linked to HIV treatment or PrEP, those with symptoms but no mpox testing reported fewer such links. This suggests targeted outreach is needed to reduce structural barriers to mpox services among GBMSM in rural areas, Black and Hispanic or Latino GBMSM, and GBMSM living with HIV. Sustaining and scaling community-tailored messaging to promote testing and vaccination represent critical interventions for mpox control among GBMSM in the United States.

The effect of sample site and collection procedure on identification of SARS-CoV-2 infection

BACKGROUND

Sample collection is a key driver of accuracy in the diagnosis of SARS-CoV-2 infection. Viral load may vary at different anatomical sampling sites and accuracy may be compromised by difficulties obtaining specimens and the expertise of the person taking the sample. It is important to optimise sampling accuracy within cost, safety and accessibility constraints.

OBJECTIVES

To compare the sensitivity of different sampling collection sites and methods for the detection of current SARS-CoV-2 infection with any molecular or antigen-based test.

SEARCH METHODS

Electronic searches of the Cochrane COVID-19 Study Register and the COVID-19 Living Evidence Database from the University of Bern (which includes daily updates from PubMed and Embase and preprints from medRxiv and bioRxiv) were undertaken on 22 February 2022. We included independent evaluations from national reference laboratories, FIND and the Diagnostics Global Health website. We did not apply language restrictions.

SELECTION CRITERIA

We included studies of symptomatic or asymptomatic people with suspected SARS-CoV-2 infection undergoing testing. We included studies of any design that compared results from different sample types (anatomical location, operator, collection device) collected from the same participant within a 24-hour period.

DATA COLLECTION AND ANALYSIS

Within a sample pair, we defined a reference sample and an index sample collected from the same participant within the same clinical encounter (within 24 hours). Where the sample comparison was different anatomical sites, the reference standard was defined as a nasopharyngeal or combined naso/oropharyngeal sample collected into the same sample container and the index sample as the alternative anatomical site. Where the sample comparison was concerned with differences in the sample collection method from the same site, we defined the reference sample as that closest to standard practice for that sample type. Where the sample pair comparison was concerned with differences in personnel collecting the sample, the more skilled or experienced operator was considered the reference sample. Two review authors independently assessed the risk of bias and applicability concerns using the QUADAS-2 and QUADAS-C checklists, tailored to this review. We present estimates of the difference in the sensitivity (reference sample (%) minus index sample sensitivity (%)) in a pair and as an average across studies for each index sampling method using forest plots and tables. We examined heterogeneity between studies according to population (age, symptom status) and index sample (time post-symptom onset, operator expertise, use of transport medium) characteristics.

MAIN RESULTS

This review includes 106 studies reporting 154 evaluations and 60,523 sample pair comparisons, of which 11,045 had SARS-CoV-2 infection. Ninety evaluations were of saliva samples, 37 nasal, seven oropharyngeal, six gargle, six oral and four combined nasal/oropharyngeal samples. Four evaluations were of the effect of operator expertise on the accuracy of three different sample types. The majority of included evaluations (146) used molecular tests, of which 140 used RT-PCR (reverse transcription polymerase chain reaction). Eight evaluations were of nasal samples used with Ag-RDTs (rapid antigen tests). The majority of studies were conducted in Europe (35/106, 33%) or the USA (27%) and conducted in dedicated COVID-19 testing clinics or in ambulatory hospital settings (53%). Targeted screening or contact tracing accounted for only 4% of evaluations. Where reported, the majority of evaluations were of adults (91/154, 59%), 28 (18%) were in mixed populations with only seven (4%) in children. The median prevalence of confirmed SARS-CoV-2 was 23% (interquartile (IQR) 13%-40%). Risk of bias and applicability assessment were hampered by poor reporting in 77% and 65% of included studies, respectively. Risk of bias was low across all domains in only 3% of evaluations due to inappropriate inclusion or exclusion criteria, unclear recruitment, lack of blinding, nonrandomised sampling order or differences in testing kit within a sample pair. Sixty-eight percent of evaluation cohorts were judged as being at high or unclear applicability concern either due to inflation of the prevalence of SARS-CoV-2 infection in study populations by selectively including individuals with confirmed PCR-positive samples or because there was insufficient detail to allow replication of sample collection. When used with RT-PCR • There was no evidence of a difference in sensitivity between gargle and nasopharyngeal samples (on average -1 percentage points, 95% CI -5 to +2, based on 6 evaluations, 2138 sample pairs, of which 389 had SARS-CoV-2). • There was no evidence of a difference in sensitivity between saliva collection from the deep throat and nasopharyngeal samples (on average +10 percentage points, 95% CI -1 to +21, based on 2192 sample pairs, of which 730 had SARS-CoV-2). • There was evidence that saliva collection using spitting, drooling or salivating was on average -12 percentage points less sensitive (95% CI -16 to -8, based on 27,253 sample pairs, of which 4636 had SARS-CoV-2) compared to nasopharyngeal samples. We did not find any evidence of a difference in the sensitivity of saliva collected using spitting, drooling or salivating (sensitivity difference: range from -13 percentage points (spit) to -21 percentage points (salivate)). • Nasal samples (anterior and mid-turbinate collection combined) were, on average, 12 percentage points less sensitive compared to nasopharyngeal samples (95% CI -17 to -7), based on 9291 sample pairs, of which 1485 had SARS-CoV-2. We did not find any evidence of a difference in sensitivity between nasal samples collected from the mid-turbinates (3942 sample pairs) or from the anterior nares (8272 sample pairs). • There was evidence that oropharyngeal samples were, on average, 17 percentage points less sensitive than nasopharyngeal samples (95% CI -29 to -5), based on seven evaluations, 2522 sample pairs, of which 511 had SARS-CoV-2. A much smaller volume of evidence was available for combined nasal/oropharyngeal samples and oral samples. Age, symptom status and use of transport media do not appear to affect the sensitivity of saliva samples and nasal samples. When used with Ag-RDTs • There was no evidence of a difference in sensitivity between nasal samples compared to nasopharyngeal samples (sensitivity, on average, 0 percentage points -0.2 to +0.2, based on 3688 sample pairs, of which 535 had SARS-CoV-2).

AUTHORS' CONCLUSIONS

When used with RT-PCR, there is no evidence for a difference in sensitivity of self-collected gargle or deep-throat saliva samples compared to nasopharyngeal samples collected by healthcare workers when used with RT-PCR. Use of these alternative, self-collected sample types has the potential to reduce cost and discomfort and improve the safety of sampling by reducing risk of transmission from aerosol spread which occurs as a result of coughing and gagging during the nasopharyngeal or oropharyngeal sample collection procedure. This may, in turn, improve access to and uptake of testing. Other types of saliva, nasal, oral and oropharyngeal samples are, on average, less sensitive compared to healthcare worker-collected nasopharyngeal samples, and it is unlikely that sensitivities of this magnitude would be acceptable for confirmation of SARS-CoV-2 infection with RT-PCR. When used with Ag-RDTs, there is no evidence of a difference in sensitivity between nasal samples and healthcare worker-collected nasopharyngeal samples for detecting SARS-CoV-2. The implications of this for self-testing are unclear as evaluations did not report whether nasal samples were self-collected or collected by healthcare workers. Further research is needed in asymptomatic individuals, children and in Ag-RDTs, and to investigate the effect of operator expertise on accuracy. Quality assessment of the evidence base underpinning these conclusions was restricted by poor reporting. There is a need for further high-quality studies, adhering to reporting standards for test accuracy studies.

Multiplexed Detection Strategies for Biosensors Based on the CRISPR-Cas System

A growing number of applications require simultaneous detection of multiplexed nucleic acid targets in a single reaction, which enables higher information density in combination with reduced assay time and cost. Clustered regularly interspaced short palindromic repeats (CRISPR) and the CRISPR-Cas system have broad applications for the detection of nucleic acids due to their strong specificity, high sensitivity, and excellent programmability. However, realizing multiplexed detection is still challenging for the CRISPR-Cas system due to the nonspecific collateral cleavage activity, limited signal reporting strategies, and possible cross-reactions. In this review, we summarize the principles, strategies, and features of multiplexed detection based on the CRISPR-Cas system and further discuss the challenges and perspective.

Proposing the observational-implementation hybrid approach: designing observational research for rapid translation

We propose the observational-implementation hybrid approach-the incorporation of implementation science methods and measures into observational studies to collect information that would allow researchers to anticipate, estimate, or infer the effects of interventions and implementation strategies. Essentially, we propose that researchers collect implementation data early in the research pipeline, in situations where they might not typically be thinking about implementation science. We describe three broad contextual scenarios through which the observational-implementation hybrid approach would most productively be applied. The first application is for observational cohorts that individually enroll participants-either for existing (to which implementation concepts could be added) or for newly planned studies. The second application is with routinely collected program data, at either the individual or aggregate levels. The third application is to the collection of data from study participants enrolled in an observational cohort study who are also involved in interventions linked to that study (e.g., collecting data about their experiences with those interventions). Examples of relevant implementation data that could be collected as part of observational studies include factors relevant to transportability, participant preferences, and participant/provider perspectives regarding interventions and implementation strategies. The observational-implementation hybrid model provides a practical approach to make the research pipeline more efficient and to decrease the time from observational research to health impact. If this approach is widely adopted, observational and implementation science studies will become more integrated; this will likely lead to new collaborations, will encourage the expansion of epidemiological training, and, we hope, will push both epidemiologists and implementation scientists to increase the public health impact of their work.

Implementing SARS-CoV-2 antigen testing scale-up in Rwanda: retrospective analysis of national programme data and qualitative findings

OBJECTIVES

Reverse transcriptase PCR is the most sensitive test for SARS-CoV-2 diagnosis. However, the scale-up of these tests in low-income and middle-income countries (LMICs) has been limited due to infrastructure and cost. Antigen rapid diagnostic tests are an alternative option for diagnosing active infection that may allow for faster, easier, less expensive and more widespread testing. We compared the implementation of antigen and PCR testing programmes in Rwanda.

DESIGN

We retrospectively reviewed routinely collected PCR and antigen testing data for all reported tests conducted nationally. We administered semiquantitative surveys to healthcare workers (HCWs) involved in COVID-19 testing and care and clients receiving antigen testing.

SETTING

Rwanda, November 2020-July 2021.

PARTICIPANTS

National SARS-CoV-2 testing data; 49 HCWs involved in COVID-19 testing and care; 145 clients receiving antigen testing.

INTERVENTIONS

None (retrospective analysis of programme data).

PRIMARY AND SECONDARY OUTCOME MEASURES

Test volumes, turnaround times, feasibility and acceptability of antigen testing.

RESULTS

Data from 906 204 antigen tests and 445 235 PCR tests were included. Antigen testing increased test availability and case identification compared with PCR and had a median results return time of 0 days (IQR: 0-0). In contrast, PCR testing time ranged from 1 to 18 days depending on the sample collection site/district. Both HCWs and clients indicated that antigen testing was feasible and acceptable. Some HCWs identified stockouts and limited healthcare staff as challenges.

CONCLUSIONS

Antigen testing facilitated rapid expansion and decentralisation of SARS-CoV-2 testing across lower tier facilities in Rwanda, contributed to increased case identification, reduced test processing times, and was determined to be feasible and acceptable to clients and providers. Antigen testing will be an essential component of SARS-CoV-2 test and treat programmes in LMICs.

Trade-offs during the COVID-19 pandemic: A discrete choice experiment about policy preferences in Portugal

The need to control the sanitary situation during the COVID-19 pandemic has led governments to implement several restrictions with substantial social and economic impacts. We explored people's trade-offs in terms of their income, life restrictions, education, and poverty in the society, compared to their willingness to avoid deaths. We applied a web-based discrete choice experiment to elicit preferences of the Portuguese citizens for these attributes and computed the marginal rate of substitution in terms of avoided deaths. We recorded 2,191 responses that faced the possibility of having 250 COVID-19 related deaths per day as the worst possible outcome from the choice levels presented. Estimates suggested that individuals would be willing to sacrifice 30% instead of 10% of their income to avoid approximately 47 deaths per day during the first six months of 2021. For the same period, they would also accept 30% of the students' population to become educationally impaired, instead of 10%, to avoid approximately 25 deaths; a strict lockdown, instead of mild life restrictions, to avoid approximately 24 deaths; and 45% of the population to be in risk of poverty, instead of 25%, to avoid approximately 101 deaths. Our paper shows that avoiding deaths was strongly preferred to the remaining societal impacts; and that being a female, as well as working on site, led individuals to be more averse to such health hazards. Furthermore, we show how a DCE can be used to assess the societal support to decision-making during times of crisis.

Parental refusal and hesitancy of vaccinating children against COVID-19: Findings from a nationally representative sample of parents in the U.S

The uptake rate of COVID-19 vaccines among children remains low in the U.S. This study aims to 1) identify sociodemographic and behavioral factors influencing parental refusal of vaccinating children, and 2) quantify the relative importance of vaccine characteristics in parental hesitancy of vaccinating children. An online survey was conducted from October to November 2021 among a probability-based, representative sample of 1456 parents with children under age 18. The survey included a discrete choice experiment asking parents to choose between two hypothetical COVID-19 vaccine alternatives with varying levels of characteristics in 10 hypothetical scenarios. Logistic regressions were used to estimate parental refusal (refused to choose any vaccine alternatives in all hypothetical scenarios) and random parameter logit regressions were used to estimate parental hesitancy (choice of vaccine alternatives depended on vaccine characteristics) of vaccinating children. About 20% parents refused to vaccinate children. The refusal is predicted by parents' sociodemographic characteristics, political orientation, vaccination status, and parents' and children's previous exposure with COVID-19. Among parents who were willing to consider vaccinating children, the most important vaccine characteristics are risk of severe side effects (31.2% relative importance) and effectiveness (30.7%), followed by protection duration (22.6%), local coverage (9.4%), and hospitalization rate of unvaccinated children (6.1%). Our findings imply that policymakers and public health professionals could develop outreach programs at community level to encourage specific subgroups and focus on vaccination depoliticization. Effectively communicating the low risk of severe side effects and high effectiveness of the vaccines may relieve some of the parental hesitancy.